i have heard to soak them in a bucket of seafoam or chemtool cleaner overnite.

Any other personal preferences on cleaners?

 

There are companies that you can send your fuel injectors to that will clean and test them etc. http://fuelinjectorman.com/ is one that I have found, but I have not used them..

When I rebuilt the top end on my girly's 3.8L there was a bunch of gunk all over the injectors due to a bad intake gasket leak, and while removing them I managed to get that gunk on the injector tips. I didn't have time to send them out to a service, so I went with the soaking method. I cut the top off a large soda bottle, placed the injectors inside and sprayed a couple cans of Carb & Choke cleaner in the bottle till the injectors were completely submerged and let them soak for 48 hours (lightly shaking the bottle around to help get rid of air bubbles and move the gunk around every 12 hours or so). After that, I gave each injector a good quirt of cleaner on the inlet and outlet, replaced the upper and lower o-rings and installed them... Car runs like a top...

 

http://www.witchhunter.com/ is who I use to clean my injectors.